Question 1

During a sprint race, athletes must respond to the starting gun as quickly as possible. Which physiological process is most directly responsible for the rapid transmission of the signal from the ear to the leg muscles?

Accepted Answer

Propagation of an action potential along motor neurons

Question 2

Which of the following best describes the role of the Na⁺/K⁺ pump in maintaining neural stability during repeated muscle contractions?

Accepted Answer

It prevents dissipation of ion gradients by actively transporting Na⁺ out and K⁺ in.

Question 3

According to World Athletics rules, an athlete is disqualified for a false start if they move within how many seconds after the gun fires?

Accepted Answer

0.1 seconds

Question 4

Which equation best represents the electrochemical gradient for Na⁺ during an action potential?

Accepted Answer

$$E_{Na} = \frac{RT}{zF} \ln \left( \frac{[Na^+]_{out}}{[Na^+]_{in}} \right)$$

Question 5

A patient experiences neuromuscular fatigue after isometric exercise. Which cellular activity is most likely altered?

Accepted Answer

ATPase activity in muscle cells

Question 6

Which of the following is TRUE regarding the propagation of an action potential along a neuron?

Accepted Answer

It is maintained by the Na⁺/K⁺ pump preventing dissipation of ion gradients.

Question 7

If the Na⁺/K⁺ pump in a neuron is inhibited, what is the most likely consequence?

Accepted Answer

Ion gradients will dissipate, leading to loss of action potential propagation.

Question 8

Which of the following best explains why only a small percentage of ions actually move during an action potential?

Accepted Answer

The change in membrane potential is due to selective permeability and rapid ion channel opening.

Question 9

During a false start in a sprint, which neural event most likely occurs prematurely?

Accepted Answer

Depolarization of motor neurons before the gun fires

Question 10

Which of the following is a direct effect of altered ATPase activity following isometric exercise?

Accepted Answer

Reduced ability to restore ion gradients after muscle contraction

Question 11

Which formula describes the relationship between membrane potential ($$V_m$$), ion concentrations, and permeability for multiple ions?

Accepted Answer

$$V_m = \frac{RT}{F} \ln \left( \frac{P_{K^+}[K^+]_{out} + P_{Na^+}[Na^+]_{out} + P_{Cl^-}[Cl^-]_{in}}{P_{K^+}[K^+]_{in} + P_{Na^+}[Na^+]_{in} + P_{Cl^-}[Cl^-]_{out}} \right)$$

Question 12

In the context of sports performance, why is the timing of neural commands critical for athletes at the starting blocks?

Accepted Answer

Precise timing ensures correct response to the starting signal, preventing false starts.

Question 13

Which of the following best describes the sequence of events in the propagation of an action potential?

Accepted Answer

Opening of Na⁺ channels, depolarization, opening of K⁺ channels, repolarization

Question 14

Which process is most directly responsible for restoring the resting membrane potential after an action potential?

Accepted Answer

Active transport of Na⁺ and K⁺ by the Na⁺/K⁺ pump

Question 15

A sprinter reacts to the starting gun in 0.08 seconds. According to the World Athletics rule, what is the outcome?

Accepted Answer

The athlete is disqualified for a false start.

Question 16

Which of the following is a consequence of neuromuscular fatigue on action potential propagation?

Accepted Answer

Slower propagation due to impaired ion gradient restoration

Question 17

Which of the following is NOT a function of the Na⁺/K⁺ pump in neurons?

Accepted Answer

Generating action potentials

Question 18

Which scenario best illustrates the importance of ion gradients in muscle contraction during athletic performance?

Accepted Answer

A runner experiences muscle cramps due to disrupted Na⁺/K⁺ gradients.

Question 19

Which of the following would most likely result from a malfunction of the Na⁺/K⁺ pump in skeletal muscle cells?

Accepted Answer

Muscle cells lose the ability to generate repeated contractions.

Neurophysiology: Action Potentials and Neural Stability

Study Guide - Practice Questions

Study Guide - Flashcards